When to Plant Ageratum in Altoona, WI

One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant ageratum in Altoona should be estimated by referring to the USDA zone info.


Planting Calendar for Ageratum

Frost tolerance for ageratum: Not tolerant of frost.
When to plant: After the last frost.

You really shouldn't plant ageratum until after the last frost because they are not cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant ageratum
Possibly ok, but a risky time to plant ageratum
Probably not a good time to plant ageratum

The earliest that you can plant ageratum in Altoona is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant ageratum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your ageratum may not have a chance to grow to maturity. Starting your ageratum indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Altoona. In the coldest months of winter you should expect an average low temperature of -25°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Altoona and it is different every year. Since half of the time in Altoona there is a last frost after May 15 be ready to protect your ageratum if you have a surprise late frost.

USDA Zone Info for Altoona

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-25°F
Highest Expected Low-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Altoona

You may be interested in your other planting guides for Altoona.